I misread your question the first time. Put the aluminum foil on the back side of the rectangular piece of card stock that says Freeantennas on it, as you asked. Use a knife to cut the 6 slots that are printed on it. The piece that says Windsurfer on it will get shaped so that the tabs on it go in the slots of the rectangular piece. This will force the rectangular piece into a curved "U" parabolic shape.... The two "+" marks on the Windsurfer piece get opened up to slide over the wireless router antenna.